Michael j



(No Model.)

M. J. OSULLIVAN.

- ELECTRIC ARG LAMP.

No. 258,466. Patented May 23, 1882.

` NA PETERS, Phum-Limognphar. Wuhngmn. D. C.

g UNTTED STATES PATENT CEETTTEO MICHAEL J. OSULLIVAN, CF BALTIMORE,MARYLAND, ASSIGNOR TO THE AMERICAN ELECTROPHORE COMPANY, OF IVASHINGTON,l). C.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 258,466, dated May 23,1882.

Application filed December 19, 1881. l(No model.)

To all whom tt may concern Be it known that I, MlcHAEL J. OSULLI- VAN,of the city of Baltimore, in the countyot' Baltimore and State ofMaryland, have invented a certain new and useful Improvement inElectric-Arc Lamps; and I do hereby declare the following to be a full,clear, and exact description ot' the same, reference being had to theaccompanying drawings and the letters of reference marked thereon,forming a part ot' the same.

In arc lamps as at present constructed the lamp-frame, and the horn aswell when one is used, are in electrical connection with thecarbon-holders. A lamp ot' this kind is dangerous to handle, and isoften the occasion of serious accidents.

The object I have in view is to remedy the above-named defect, and alsoto accomplish this object without necessitating material changes in theform or construction of existing types of lamps. To this end I combinewith the lamp-frame a lower-carbon holder which is insulated from theframe, and an insulated covered connecting-wire leading from the properlamp terminal to said holder. I thus isolate the frame from thelower-carbon holder and its electrical connections and render itperfectly sate to handle. I also combine the upper or movable carbon rodor holder and the horn which surrounds and receives the upper end of thesame in such manner that the horn will he insulated and out ofelectrical contact with the rod, and in lamps in which the said holderhas a tubular prolongation constituting the body or cylinder and amoving element of the dash-potI suspend the plunger member of thedash-pot from a plug of hard rubber or other non-conductor materialfitted to the horn, so as to ei'ectually prevent electrical connectionfrom that source, and I further insulate the said holder from the feedmechanism containing box or case through which it passes. In this Way Iobtain a lamp which can be handled with entire safety, and which willendanger neither life nor property.

In the accompanying drawings, Figure l is a sectional elevation ofsomuch of an arc lamp t as needed for the purposes ot' explanation. Fig. 2is a view 0n enlarged scale ofthe dashpot cylinder forming partot' theupper-carbon holder. Fig. 3 is a view on like scale of the plunger, withthe plug from which it is suspended in section. Fig. 4I is a sectionalelevation ofthe lower-carbon holder, with its insulating supportingbridge-tree and parts ofthe lamp-frame adjoining the Same. Fig. 5 is aplan of the bridge-tree.

The frame Aof the lamp is ofthe usual configuration. rIhe terminals areindicated at 7c kthe latterclectrically connected in the usual way withthe upper-carbon holder E and the former in electrical connection withthe lowercarbon holder H. The conducting-wire which leads from theterminal 7c to the holder II is shown at u, covered with rubber or otheriusulating material, a', and extending through the limbs c c' of theframe, which are made hollow or tubular for this purpose. This is thepreferred arrangement, inasmuch as the wire while insulated l'rom theframe is covered by the latter throughout its length. The lowercarbonholder H is alsoinsulatcd from the frame by a bridge-tree, G, of hardrubber or other suitable material, upon which the holder should hesecured in a manner to permit ot' the usual adjustments. ln this wayIentirely insulate the frame, so that it may be handled with entiresafety while the lamp is running. rIhe horn D is made fast to the usualwooden plate and spans the top ofthe frame. Within it is, as usual, thetubular carbon-holding rod E, which forms the cylinder and moving memberofthe dash-pot, and is designed to he filled with glycerine or othersuitable liquid. Vithin it is the plunger, consisting in this instanceof disks h, fast to the plunger-rod e', which is suspended from a plug,F, made ot' hard rubber or other non-conducting material, which isscrewed into the top ot" the horn, as indicated in Fig. l. In thisway--that is to say, by the employment of a non-conducting or insulatingplug as the meansfor suspending theplungerthe carbon-holder iseffectually insulated from the horn, which latter is thus free from anyelectrical change.

In order to more effectively insure the insulation of the horn, theenlarged overflow e on top ot' the cylinder E is made ot' hard rubber orsome other suitable non-conducting material, so that in event ofaccidental contact between the two there can be no possible electriealconnection between the horn and the holder through that intermediary.The case which contains the usual carbon t'eed and regulating mechanismis indicated at B. l have not deemed it necessary to show saidmechanism, inasmuch as the same is well known and forms no part ot' myinvention. At the point Where the carbon-holder passes out from andbelow the ease l provide, instead of the usual bearing, an insulatedbearing, consisting,` in this instance ofthe hardrubber washer b,provided with a .metallic lining', b. It' more than one bearing beprovided for the carbon, each of them should be insulated from the casein this or some similar manner.

What I claim as my invention is- 1. In an are lamp, the combination,with the movable upper-carbon holder, of a horn insulated fromelectrical connection with said holder, and other parts which may beeinbraeed in the lamp-circuit, substantially as hereinbefore set forth.

2. The non-conducting or insulated plug; F, in combination with thehorn, the holder E, and the plunger, substantially as and for thepurposes hereiubet'ore set forth.

3. The holder E, surmounted by a non-conducting` overiow, e, incombination with the plunger, the non-conducting or insulated plug F,and the horn, substantially as hereinbefore set 'orth.

4. The combination ot the movable upper carbon holder, the ease or boxB, provided with insulated bearings at thepoint or points where theholder has contact with said case, and the lower-carbon holder,insulated also from said case, substantially as and t'or the purposesset forth.

5. In an arclamp, the combination, with the carbon-holders and otherparts embraced in the lamp-circuit, ot'- the horn and the frame,insulated from said parts, substantially as and tor the purposes setforth.

MICHAEL J. OSULLIVAN.

Witnesses:

0. H. MILLER, E. RAINE.

